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Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 202-241).

Thesis (Ph. D.)--Ohio State University, 2005. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2006 May 26.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xix, 94 p.; also includes graphics (some col.). Includes bibliographical references (p. 87-94). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 178-204).

Metabolomic Insights into the Pharmacological and Genetic Inhibition of Cyclooxygenase-2 William T. E. Briggs The cyclooxygenase (COX)-2 inhibitors, or “coxibs,” are excellent anti-inflammatory agents, but their reputation has been tarnished by the adverse cardiovascular (CV) events, including heart failure (HF), with which they are associated. Whilst the risk of HF represents the greatest adverse CV event signal seen with these compounds, it is also perhaps the least well understood and has often been explained away as a consequence of the thrombotic risk with which the coxibs are also associated. One recent hypothesis, put forward by Ahmetaj-Shala et al., suggests that asymmetric dimethylarginine (ADMA) may serve as a mechanistic bridge between COX-2 inhibition and HF. However, the ADMA-COX-2 hypothesis was developed based on findings in a constitutive mouse model of COX-2 knock-out (KO), which is compromised by severe developmental cardio-renal pathology, and pharmacological studies which may not accurately reflect coxib use in clinical practice. Various studies have explored the metabolic changes induced by coxib treatment. However, these studies have been limited in scope and have tended to focus on specific pathways or certain tissues/bio-fluids. This has left large regions of the metabolome, in the context of coxib-treatment, unexplored. Given that metabolic remodelling is a key feature of HF, changes in these metabolites may hold the key to understanding the pathogenesis of coxib-induced HF. L-Carnitine shuttles activated long-chain fatty acids (FAs) across the inner mitochondrial membrane to the mitochondrial matrix, where they are oxidised by β-oxidation. This is especially important in the heart, which derives the majority of its energy from the metabolism of FAs. Changes in carnitine metabolism are also seen in HF. It is therefore biologically plausible that derangements in carnitine metabolism may contribute to the pathogenesis of coxib-induced HF. This thesis employs a combination of targeted and untargeted metabolomic techniques, stable isotope labelling and quantitative reverse transcription polymerase chain reaction (RT-qPCR) to i) profile the metabolic changes induced by celecoxib and rofecoxib, in the mouse; ii) specifically interrogate the effect of celecoxib, rofecoxib and global COX-2 gene deletion on carnitine synthesis, metabolism and shuttling, and iii) explore the advantages and disadvantages of the inducible post-natal global (IPNG) COX-2 KO (COX-2-/-) mouse, an alternative to the constitutive COX-2-/- mouse used by Ahmetaj-Shala et al. The results of this thesis demonstrate that i) celecoxib and rofecoxib have similar metabolomic consequences in the mouse; ii) carnitine metabolism may be affected by celecoxib, rofecoxib and dietary composition, via a peroxisome proliferator-activated receptor-alpha (PPAR-α) mediated effect on hepatic carnitine synthesis and iii) the IPNG COX-2-/- mouse neither exhibits the severe developmental cardio-renal pathology nor the altered ADMA metabolism observed in the constitutive COX-2-/- mouse. These findings contradict those of Ahmetaj-Shala et al., oppose the ADMA-COX-2 hypothesis and highlight a potential role for carnitine metabolism and diet in coxib induced HF.

Indiana University-Purdue University Indianapolis (IUPUI) / Adolescent alcohol abuse is a global problem that initiates lifelong addiction. Alcohol use during adolescence is associated with subsequent Meth dependence in humans. Specifically, female adolescents are particularly vulnerable to serial alcohol and Meth use. However, it is unknown if prior voluntary alcohol drinking impacts subsequent Meth-taking in female adolescent rats. Both alcohol and Meth increase the prostaglandin synthesis enzyme cyclooxygenase-2 (COX-2) in the brain but the effect of serial exposure to alcohol and Meth on COX-2 has not been determined. The first study uses a novel method of serial voluntary alcohol drinking and Meth self-administration in female adolescent rats to model human patterns of co-abuse. Prior alcohol drinking did not affect subsequent Meth self-administration, but it reduced the cue-primed reinstatement of Methseeking after abstinence from Meth. Rats with a history of adolescent alcohol drinking also had increased COX-2 in the dorsal striatum, regardless of subsequent Meth selfadministration. These findings demonstrate that a history of adolescent alcohol drinking does not alter Meth self-administration but persistently reduces cue-primed Meth seeking and increases COX-2 after prolonged abstinence from alcohol. To further examine the role of COX-2 in alcohol drinking, the second study found that adolescent alcohol drinking not only increased COX-2 after four weeks of alcohol abstinence, but also increased endothelin-1 (ET-1) and prostaglandin E2 (PGE2) in the dorsal striatum. Furthermore, adolescent alcohol drinking increased alcohol drinking after abstinence, and this increase was attenuated by treatment with the COX-2 inhibitor nimesulide during abstinence. Antagonism of the interaction between PGE2 and its receptor 1 (EP1) also attenuated the increase in relapse drinking and restored alcohol drinking to the rate of alcohol naïve rats. Overall, these experiments identified a prostaglandin-mediated mechanism that is a putative target for the treatment of alcohol relapse following abstinence in individuals with a history of adolescent alcohol abuse.

No description available.

No / Cryptolepis sanguinolenta and its bioactive alkaloid, cryptolepine have shown anti-inflammatory activity. However, the underlying mechanism of anti-inflammatory action in neuronal cells has not been investigated. In the present study we evaluated an extract of C. sanguinolenta (CSE) and cryptolepine (CAS) on neuroinflammation induced with IL-1β in SK-N-SH neuroblastoma cells. We then attempted to elucidate the mechanisms underlying the anti-neuroinflammatory effects of CAS in SK-N-SH cells. Cells were stimulated with 10 U/ml of IL-1β in the presence or absence of different concentrations of CSE (25–200 μg/ml) and CAS (2.5–20 μM). After 24 h incubation, culture media were collected to measure the production of PGE2 and the pro-inflammatory cytokines (TNFα and IL-6). Protein and gene expressions of cyclooxygenase (COX-2) and microsomal prostaglandin synthase-1 (mPGES-1) were studied by immunoblotting and qPCR, respectively. CSE produced significant (p < 0.05) inhibition of TNFα, IL-6 and PGE2 production in SK-N-SH cells. Studies on CAS showed significant and dose-dependent inhibition of TNFα, IL-6 and PGE2 production in IL-1β-stimulated cells without affecting viability. Pre-treatment with CAS (10 and 20 μM) was also found to inhibit IL-1β-induced protein and gene expressions of COX-2 and mPGES-1. Further studies to determine the mechanism of action of CAS showed inhibition of NF-κBp65 nuclear translocation, but not IκB phosphorylation. At 10 and 20 μM, CAS inhibited IL-1β-induced phosphorylation of p38 MAPK. Studies on the downstream substrate of p38, MAPK-activated protein kinase 2 (MAPKAPK2) showed that CAS produced significant (p < 0.05) and dose dependent inhibition of MAPKAPK2 phosphorylation in IL-1β-stimulated SK-N-SH cells. This study clearly shows that cryptolepine (CAS) inhibits neuroinflammation through mechanisms involving inhibition of COX-2 and mPGES-1. It is suggested that these actions are probably mediated through NF-κB and p38 signalling.

Yu, Le. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 171-198). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.